In their blockbuster book, Made to Stick, Chip and Dan Heath tell the tale of Tappers and Listeners. A PhD Psychology student at Stanford divided a test subjects into two groups, tappers and listeners. Here’s how they tell it:

Tappers received a list of 25 well known songs, such as “Happy Birthday to You” and “The Star Spangled Banner.” Each Tapper was asked to pick out a song and tap out the rhythm to a Listener (by knocking on a table). The Listener’s job was to guess the song, based on the rhythm being tapped.

During the experiment 120 songs were tapped out. So guess how many of them were correctly guessed by the listeners? Seriously, go ahead and take a guess on what percentage of those songs the listeners managed to identify.

Answer: only three songs were guessed correctly. That’s 3 out of 120, or 2.5%!

So what’s the point?

The tappers all thought that the listeners would probably guess at least half the songs they tapped. Why? Because the tappers were hearing the song in their head as they tapped. But the listeners don’t have that tune playing in their head. They just hear a disconnected bunch of taps.

And that same Tapper-Listener disconnect — called “The Curse of Knowledge” — occurs all the time between PPC Ad Writers and Searchers, especially if the ad writer works for the business.

When you’re knowledge of the business vastly exceeds the customers, you almost begin to assume that everyone else knows what you know. That it’s obvious. And that’s one way you can unwittingly sabotage your PPC Ad Results. This contest is a perfect example of that:

The losing ad thought it was obvious that Turquoise Jewelry crafted by Southwest Indian Tribes would be the traditional silver and turquoise designs that the employees in that company are doubtlessly familiar with — jewelry they probably thought that EVERYBODY would be familiar with.

But there are lots of styles of turquoise jewelry, and not everyone is familiar with the kind crafted by the Indian Tribes listed. That’s why specifying “Steling Silver Turquoise Jewelry,” as the winning ad does, helps boost performance — it fills the listener in on the tune the advertiser is singing, rather than assuming they can fill it in on their own.

So take a tip from the Boosters and don’t assume it’s obvious.

Ask yourself what you already ARE assuming the searcher knows that maybe she doesn’t. Then test ads that make that information more explicit, and see what kind of results you get. In this case it got a CTR boost of 38%